The shrimps came from a local breeder.
Water change 10% every 2 weeks.
I think there is 50 now.
How can I test the RO water?
Check the TDS. 0-10 is acceptable, anything else is bad.
Agreed, also if you want to test for bacteria:
boil water to sanitize mason jar/lid 20 min,
use sealed jar to collect free flowing (wait min or 2 before collecting sample after water flowing) RO water from source.
boil vegetable (broccoli ) for min ten minutes, with sterile boiled twizzers put vegetable in container with RO water.
Seal, be as sanitary as possible.
Wait 10 days, is water cloudy = bacteria.
Reading this, it may be too much work for what probably is not that big of a deal... I digress.
But you may just worry about TDS
as its its more appicable.